A great deal of effort has been devoted to the development of polyimides and polyimide foams having useful properties. One promising area of application for flexible polyimide foams is as a potential substitute for flammable polyurethane foams in aircraft seat cushions and the like, where the fire resistance and lightness of polyimides would be of considerable advantage.
Unfortunately, previously known flexible polyimide foams generally suffer from either or both of two shortcomings limiting their usefulness for seat cushion applications:
1. Lack of sufficient compression fatigue life, which means that the foam prematurely loses its resiliency (ability to return to its original shape) after repeated compression during usage.
2. Lack of sufficient softness which causes the cushion to be stiffer and less comfortable than desired.